i see this song as a guy telling his girl that even tho he loves her, loves her so bloody much, he appologises to her because he knows that down the track he will fuck it all up and cause her pain. he knows his "heart will stray before too long". he will find another girl to fall in love with, but for now he loves her. he just wants to warn her before he lies, before he cheats, before anything goes wrong. he's a bastard. he's done it many times before. he will wreck her life, even tho he doesnt want to now, he knows he will. he's trying to save her from the pain she will eventually have to face.
i see this song as a guy telling his girl that even tho he loves her, loves her so bloody much, he appologises to her because he knows that down the track he will fuck it all up and cause her pain. he knows his "heart will stray before too long". he will find another girl to fall in love with, but for now he loves her. he just wants to warn her before he lies, before he cheats, before anything goes wrong. he's a bastard. he's done it many times before. he will wreck her life, even tho he doesnt want to now, he knows he will. he's trying to save her from the pain she will eventually have to face.